Conventional positron emission computed tomography (PET) devices are known that generate a PET image representing the distribution in a subject of an agent that is labeled with positron-emitting radionuclides. A PET device generally includes a ring-shaped PET detector that is arranged so as to enclose a subject. The PET detector is formed, for example, by arranging, in a ring, multiple detector modules including scintillators that convert gamma rays (including annihilation radiation) into visible light. For PET devices, there may be a requirement to reduce the cost of manufacturing the PET detectors and, for example, to reduce the thickness of the scintillators of the PET detectors in order to improve TOF (time of flight) temporal resolution.
In conventional PET devices, however, when the thickness of the scintillators of the PET detector is reduced, the possibility increases of gamma rays passing without being detected by the PET detector, which may decrease the image quality of a captured PET image.